NES emulation journal: Do not abuse substances

Happy new year every body! My NES emulator is taking shape! I am currently implementing side-scrolling and the main target is Super Mario Bros.

The fine-x for smooth scrolling is set with the PPU register 0x2005. Fine-x is a 3-bit value (so, between 0 and 7) and will decide what bit to select from the tile byte when rendering a background pixel.

My implementation is not complete yet (I correctly fetch the low plane bit but not the high plane bit), which gives me something totally funky. Mario on mushrooms!

Enjoy!